Parent Post implied that had the DDR had these sonic weapons the Berlin Wall would not have fallen... as if The DDR would not have had the willingness to put a stop to it if they wanted to. What happened is they announced publicly that they had a change of heart and would let people cross. And so people did.
If you're leading a country as a stong[man] and you want to retain control, it is imperative you use strong tactics --anything less is seen as a weakness by (good or bad) adversaries, and rightly so.
It’s a difficult comparison to North Korea because the regime is not in that situation. The situation is more nuanced than that. I elaborated on possible motivations for using nonlethal force earlier... In the case of North Korea, they also might prefer to not kill citizens who they use for labor.
I wasn’t intending to discuss specific events or political situations, though. I meant to merely touch on the political dynamics of non-lethal crowd control.